Wilson, Motor Endings of the Frog. 3 



(tertiary fibrils) may proceed to other muscle cells ; or they 

 divide repeatedly into ever finer fibrils till ultimately perhaps, 

 elementary fibrillae result. He often saw very fine nerve 

 fibrillae pass out of a muscle cell into the neighboring con- 

 nective tissue and it might be, branch there. As to the ulti- 

 mate fate of the finest fibrillae he is uncertain, but he declares : 

 "Es kommt mir an wahrscheinlichsten vor, das sie mit anderen 

 ahnlichen ein intermuskulares Elementargitter bilden." ^ 



The results of Apathy led Ruffini in 1900 to re-examine 

 nerve endings in the human muscle which he had stained by 

 his chloride of gold method. Here he found in some of his 

 specimens fine fibers which he had not previously noted and 

 which he now described under the name of ultra-terminal 

 fibrillae. These are very fine, non-medullated fibrillae which 

 pass out from the motor end-plate. "This fibrilla" (ultra- 

 terminal), he says, "after an unbranched course, more or less 

 long, may terminate in the same muscular fiber on which rests 

 the plate from which it is derived, or, as is often the case, put 

 itself into relation with one of the neighboring striated fibers. 

 From it collaterals may at times come off." It may end in a 

 swelling or in a second small plate (plaquette) ; in one case 

 from a plaquette another fibre was seen to pass out, but its 

 course could not be followed. Summing up the results of his 

 examination, he says: "The motor plates in man do not rep- 

 resent the true and real terminations of motor nerves, because 

 beyond the plate there exists a well demonstrable anatomical 

 continuity shown by non-myelinated nerve fibrillae of which we 

 do not know the last relations." - This is obviously a state- 

 ment very closely akin to that given by Apathy in the sum- 

 ming up of his results. 



Later Peroncito, working with Ruffini and using his gold 

 chloride method, describes in Lacerta muralis and Lacerta 

 viridis the ultraterminal fibrilla as separating itself from the 



1 Ibid., p. 695. 



^ Ruffini : Sulle fibrille nervose ultraterminale nelle piastre motrici dell' 

 uomo. Rivista di pat. nerv. e ment., 1900, V. 5. 



